Statements": 
- fix a couple of net->buff overruns in libmysql,
- check in the server that statement parameter count is less than
  65535 (maximum value supported by prepared statements protocol).
 


libmysql/libmysql.c:
  Bug#5194 "Bulk Insert Failures with Prepared Statements":
  - clean up my_realloc_str()
  - ensure that net buffer has space when storing null bits and
    parameter typecodes.
sql/net_serv.cc:
  - set net->last_errno if packet is too big, even on client
    (Why was it ifdefed before?)
sql/sql_prepare.cc:
  Bug#5194 "Bulk Insert Failures with Prepared Statements":
  - if placeholder count is bigger than 65535, give error.
    We have only 2 bytes reserved for transferring placeholder count
    in 4.1 protocol.
  - can't add a proper error code and message in 4.1 because of
    possible merge difficulties."
tests/client_test.c:
  A test case for Bug#5194 "Bulk Insert Failures with Prepared 
  Statements".